“Undoubtedly the most spectacular aspect of our 16-year study, is that it has delivered what is now considered to be the best empirical evidence that super-massive black holes do really exist,” Genzel continues. “The stellar orbits in the galactic centre show that the central mass concentration of four million solar masses must be a black hole, beyond any reasonable doubt.”

There's a common notion that at the edge of every black hole lies a back door to the universe — an exit from reality into a new realm where fundamental laws of nature, like time, no longer behave the way that we understand them.

What happens once you cross this threshold is a long-standing mystery that the world's leading scientists have been pondering for decades with little headway.

Now, a recent paper presented at a conference in Paris this week has proposed a solution by looking at black holes in a completely different way.

Taking a novel approach to this age-old problem, the theory proposes that there is no back door to the universe in the first place. Instead, black holes are impenetrable bodies, called fuzzballs. Fuzzballs (yes, fuzzballs) are the new black holes Samir Mathur, a professor of physics at The Ohio State University and sole author of the paper, says as you approach the fuzzball, your body will be destroyed but, oddly enough, you will not die. Rather, you'll be transformed into a copy of yourself, in the form of a hologram, that is forever embedded onto the surface of the fuzzball.

Mathur describes the surface as a thin fuzzy region of space instead of smooth, distinct feature, which is how he came up with the name "fuzzball".

When he first announced his fuzzball theory in 2003, it excited the scientific community because it offered a resolution to an outstanding paradox about black holes.

This paradox was originally discovered by astrophysicist Stephen Hawking more than 40 years ago and scientists have been attempting to explain it ever since.

However, Mathur's original calculations didn't conform to other well-established theories that describe the nature of black holes. So, he's spent over 15 years molding and maturing his argument.

Now, his latest paper has taken a significant step forward, suggesting that his picture of black holes as the holographic copy machines of the universe, while bizarre, could mean that fuzzballs truly are how scientists should be thinking about these mysterious cosmic beasts to better understand their behavior.

But some scientists are skeptical of Mathur's conclusions. Although they support his novel view of black holes, they suggest you won't survive your encounter with a fuzzball, at all, but suffer a fiery death. The most extreme environments in spaceWhat makes black holes so exotic is their powerful gravitational grip, which acts like a deep well in space, warping the space and time around and within.

Moreover, this grip has the power to swallow everything that passes too close, including light. This means anything that falls into the well never returns, which makes it nearly impossible to determine what happens beyond the edge of a black hole.

That didn't stop Hawking from first attempting to find some answers in the early '70s.

Unlike Mathur, Hawking pictured black holes with back doors through which material was pulled by gravity. So, Hawking began to explore what happens just outside of that door, moments before crossing over to the dark side for eternity.

What he found in 1976 from following the well-established laws of physics originally set down by Albert Einstein and Paul Dirac and many others, was shocking: Black holes don't just consume material through their back doors. They also emit it in the form of radiation. A pesky paradox While this was a momentous discovery — the radiation has since been named Hawking radiation — it generated a perplexing issue, called the black hole information paradox, that scientists have yet to resolve.Hawking radiation is generated from whatever falls first into a black hole, according to Hawking's theory.

Some of what falls in gets spit back out while the rest is trapped inside of the black hole, where it's eventually destroyed and lost forever. This is where the paradox arises: One of the most fundamental concepts in physics states that no material in the universe can be completely lost or destroyed, which directly contradicts Hawking's original assumption.

Other than that small problem, the famous astrophysicist's logic was fool proof. And scientists today, including Mathur, still consider Hawking radiation a plausible component of black holes, although it has yet to be observed.

Nearly 30 years later, Hawking hasn't offered a convincing solution to the paradox he discovered, but Mathur might have. What Mathur has done differently is to think of black holes as a solid surface that has no back door. Solving the information paradox The fuzzball black holes that Mathur pictures are impenetrable and, therefore, don't have a region where material can fall into them. Rather, any object attracted by a fuzzball's gravitational pull will fall onto the surface.When that happens, a near-perfect copy of the objects is created in the form of a hologram. That hologram goes on to live on the surface of the black hole, while the original copy feeds the fuzzball.

"The original copy is destroyed. More precisely, the data making up the original copy gets transformed to a new form, which is data on the surface of the fuzzball,” Mathur told Business Insider in an email. "When matter falls on the surface, this surface gets more energy, and it expands.”

When Mathur was first exploring this theory at the turn of the century, his original calculations suggested that your holographic twin was a perfect copy of your original self. However, other scientists argued that a perfect copy was impossible because the universe tends to favor imperfection.

From this, Mathur has managed to settle the black hole information paradox in two ways:

By removing the exotic realm inside a black hole where information is mysteriously destroyed and lost forever.

By explaining exactly what happens to material as it reaches a black hole and how all of it is preserved and none is lost.

"The fuzzball structure resolves this paradox; that is the reason I believe in it," Mathur told Business Insider. Strings of fuzzballs To explain his assumptions mathematically, Mathur relies on a theoretical framework in physics called string theory, which suggests that all particles in the universe are made of tiny, one-dimensional strings that vibrate and interact with one another to generate the universe around us.(This idea is controversial since no one has ever observed a string. Still, string theory offers convincing solutions to some outstanding scientific mysteries like quantum gravity — also referred to as a "unified theory of everything" — so physicists are reluctant to scrap it just yet.)

Mathur's fuzzball black holes are actually giant, balled-up collections of strings. So, theoretically, when an object touches the surface of the fuzzball, its mass gets converted into light, generating a holographic copy of its former self. Other string theorists disagree, though.

Building upon Mathur's logic, a team of physicists at the University of California proposed in 2012 that anything falling onto the surface of a fuzzball would immediately be "burned to a crisp" and die. This group's "firewall" theory divided the scientific community into supporters of fuzzballs versus supporters of firewalls.

One way to resolve the issue would be a scientific experiment.

"It is hard to check the fuzzball structure explicitly by an experiment," Mathur told Business Insider in an email. "One way would be if we could ever make tiny black hole in an accelerator like [those at] CERN."

Particle accelerators slam particles together at near the speed of light, which can generate extreme environments that are similar to the early universe. Whether the world most powerful accelerators at CERN (European Organization for Nuclear Research) can produce tiny black holes this way is questionable.

Regardless, there is a growing group of scientists around the world in support of Mathur's idea who are exploring different facets of the theory. The deeper they dig, the more likely they'll discover the truth of fuzzballs.

The apocalypse is still on, apparently — at least in a galaxy about 3.5 billion light-years from here.Last winter a team of Caltech astronomers reported that a pair of supermassive black holes appeared to be spiraling together toward a cataclysmic collision that could bring down the curtains in that galaxy.The evidence was a rhythmic flickering from the galaxy’s nucleus, a quasar known as PG 1302-102, which Matthew Graham and his colleagues interpreted as the fatal mating dance of a pair of black holes with a total mass of more than a billion suns. Their merger, the astronomers calculated, could release as much energy as 100 million supernova explosions, mostly in the form of violent ripples in space-time known as gravitational waves that would blow the stars out of that hapless galaxy like leaves off a roof.Now a new analysis of the system by Daniel D’Orazio of Columbia University and his colleagues has added weight to that conclusion. Mr. D’Orazio, a graduate student, and his colleagues Zoltan Haiman and David Schiminovich propose that most of the light from the quasar is coming from a massive disc of gas surrounding the smaller of the two black holes.As the black holes and their attendant discs swing around each other at high speeds, the light from the disk that is coming toward us gets a boost from relativistic effects – a so-called Doppler boost — the same way a siren gets louder and more high-pitched as it approaches, giving rise to a periodic increase in brightness every five years.The Columbia astronomers’ model predicts that the variation would be two or three times greater in ultraviolet light than in visible light. And that is exactly what they found when they compared archival data from the Hubble Space Telescope and NASA’s Galex space telescope to the visible-light data previously analyzed by Dr. Graham’s group.“What’s big is that the Doppler boost is inevitable,” Dr. Haiman said in an email. Given reasonable assumptions about the masses of the two black holes, their model predicts the right ultraviolet data. “This is rare in ‘messy’ astronomy,” he said, “to have an indisputable clean effect, which explains the data.” Follow-up observations of ultraviolet and visible light emissions in the coming years could help the clinch the case, the authors said. Their paper was published on Wednesday in the journal Nature.Their model suggests that the black holes are orbiting each other at a distance of some 200 billion miles, less than a tenth of a light-year, a cosmic whisker. At that distance the black holes would be rapidly losing energy by radiating gravitational waves and could spiral together into the final bang in as little as 100,000 years, Dr. Haiman said, depending on their relative masses.“Basically, the more massive the holes, the faster gravitational waves drive them together, and we do require them to be as massive as allowed to be,” he said in an email. For their model to hold up, the larger of the black holes has to be a billion solar masses or more. AdvertisementContinue reading the main story AdvertisementContinue reading the main story E. Sterl Phinney, a Caltech astronomer and expert on supermassive black holes currently on sabbatical at Radboud University in the Netherlands, agreed that Dr. Haiman’s model explains the quasar variations. “So Occam’s razor makes it attractive,” he said in an email, referring to the long-held principle that physicists should adopt the simplest theory that fits the facts.But it was surprising, he said, to find a pair of supermassive black holes that have gotten so close.Black holes, predicted by Albert Einstein’s general theory of relativity, the prevailing theory of gravity, are objects so dense that not even light can escape from them. In effect they are bottomless pits in space-time. Every galaxy of note seems to have a supermassive black hole, weighing millions or billions of times as much as the sun, burping sparks of half-eaten stars and gas.When galaxies merge, their resident black holes are sent into forced marriages, orbiting each other. But without gravitational interactions with stars or interstellar gas, supermassive black holes can’t get close enough to each other to go into a rapid death spiral, a situation known as the “final parsec” problem. (A parsec is the astronomical standard of distance, 3.26 light-years.)So, as Dr. Phinney explained, unless hundreds of millions of solar masses of gas accompany the black holes, “there are not very convincing ways of getting them to smaller separations” like the black holes in PG 1302-102.At least that is the theory. If such systems are common, Dr. Phinney said, the gravitational waves emanating from them should sweep the universe and disrupt the timing of signals from pulsars, an effect that could be detected within the next few years by various ongoing programs to time pulsars.“A scientific theory is only as good as the tests which it has passed,” Mr. D’Orazio said in an email. Although general relativity has passed all of the observational and experimental tests thrown at it so far, some of its predictions can only be tested in the most extreme gravitational environments, namely black holes. “Detection of gravitational waves,” he said, “is a direct probe of this region and hence the secrets of gravity.”

Black holes earn their name because their gravity is so strong not even light can escape from them. Oddly, though, physicists have come up with a bit of theoretical sleight of hand to retrieve a speck of information that's been dropped into a black hole. The calculation touches on one of the biggest mysteries in physics: how all of the information trapped in a black hole leaks out as the black hole "evaporates." Many theorists think that must happen, but they don't know how.Unfortunately for them, the new scheme may do more to underscore the difficulty of the larger "black hole information problem" than to solve it. "Maybe others will be able to go further with this, but it's not obvious to me that it will help," says Don Page, a theorist at the University of Alberta in Edmonton, Canada, who was not involved in the work.You can shred your tax returns, but you shouldn't be able to destroy information by tossing it into a black hole. That's because, even though quantum mechanics deals in probabilities—such as the likelihood of an electron being in one location or another[/size]—[/color]the quantum waves that give those probabilities must still evolve predictably, so that if you know a wave's shape at one moment you can predict it exactly at any future time. Without such "unitarity" quantum theory would produce nonsensical results such as probabilities that don't add up to 100%.But suppose you toss some quantum particles into a black hole. At first blush, the particles and the information they encode is lost. That's a problem, as now part of the quantum state describing the combined black hole-particles system has been obliterated, making it impossible to predict its exact evolution and violating unitarity.Physicists think they have a way out. In 1974, British theorist Stephen Hawking argued that black holes can radiate particles and energy. Thanks to quantum uncertainty, empty space roils with pairs of particles flitting in and out of existence. Hawking realized that if a pair of particles from the vacuum popped into existence straddling the black hole's boundary then one particle could fly into space, while the other would fall into the black hole. Carrying away energy from the black hole, the exiting Hawking radiation should cause a black hole to slowly evaporate. Some theorists suspect information reemerges from the black hole encoded in the radiation[/size]—[/color]although how remains unclear as the radiation is supposedly random.Now, Aidan Chatwin-Davies, Adam Jermyn, and Sean Carroll of the California Institute of Technology in Pasadena have found an explicit way to retrieve information from one quantum particle lost in a black hole, using Hawking radiation and the weird concept of quantum teleportation.Quantum teleportation enables two partners, Alice and Bob, to transfer the delicate quantum state of one particle such as an electron to another. In quantum theory, an electron can spin one way (up), the other way (down), or literally both ways at once. In fact, its state can be described by a point on a globe in which north pole signifies up and the south pole signifies down. Lines of latitude denote different mixtures of up and down, and lines of longitude denote the "phase," or how the up and down parts mesh. However, if Alice tries to measure that state, it will "collapse" one way or the other, up or down, squashing information such as the phase. So she can't measure the state and send the information to Bob, but must transfer it intact.To do that Alice and Bob can share an additional pair of electrons connected by a special quantum link called entanglement. The state of either particle in the entangled pair is uncertain[/size]—[/color]it simultaneously points everywhere on the globe[/size]—[/color]but the states are correlated so that if Alice measures her particle from the pair and finds it spinning, say, up, she'll know instantly that Bob's electron is spinning down. So Alice has two electrons[/size]—[/color]the one whose state she wants to teleport and her half of the entangled pair. Bob has just the one from the entangled pair.To perform the teleportation, Alice takes advantage of one more strange property of quantum mechanics: that measurement not only reveals something about a system, it also changes its state. So Alice takes her two unentangled electrons and performs a measurement that "projects" them into an entangled state. That measurement breaks the entanglement between the pair of electrons that she and Bob share. But at the same time, it forces Bob's electron into the state that her to-be-teleported electron was in. It's as if, with the right measurement, Alice squeezes the quantum information from one side of the system to the other.Chatwin-Davies and colleagues realized that they could teleport the information about the state of an electron out of a black hole, too. Suppose that Alice is floating outside the black hole with her electron. She captures one photon from a pair born from Hawking radiation. Much like an electron, the photon can spin in either of two directions, and it will be entangled with its partner photon that has fallen into the black hole. Next, Alice measures the total angular momentum, or spin, of the black hole[/size]—[/color]both its magnitude and, roughly speaking, how much it lines up with a particular axis. With those two bits of information in hand, she then tosses in her electron, losing it forever.But Alice can still recover the information about the state of that electron, the team reports in a paper in press at Physical Review Letters. All she has to do is once again measure the spin and orientation of the black hole. Those measurements then entangle the black hole and the in-falling photon. They also teleport the state of the electron to the photon that Alice captured. Thus, the information from the lost electron is dragged back into the observable universe.Chatwin-Davies stresses that the scheme is not a plan for a practical experiment. After all, it would require Alice to almost instantly measure the spin of a black hole as massive as the sun to within a single atom's spin. "We like to joke around that Alice is the most advanced scientist in the universe," he says.The scheme also has major limitations. In particular, as the authors note, it works for one quantum particle, but not for two or more. That's because the recipe exploits the fact that the black hole conserves angular momentum, so that its final spin is equal to its initial spin plus that of the electron. That trick enables Alice to get out exactly two bits of information[/size]—[/color]the total spin and its projection along one axis[/size]—[/color]and that's just enough information to specify the latitude and longitude of quantum state of one particle. But it's not nearly enough to recapture all the information trapped in a black hole, which typically forms when a star collapses upon itself.To really tackle the black hole information problem, theorists would also have to account for the complex states of the black hole's interior, says Stefan Leichenauer, a theorist at the University of California, Berkeley. "Unfortunately, all of the big questions we have about black holes are precisely about these internal workings," he says. "So, this protocol, though interesting in its own right, will probably not teach us much about the black hole information problem in general."However, delving into the interior of black holes would require a quantum mechanical theory of gravity. Of course, developing such a theory is perhaps the grandest goal in all of theoretical physics, one that has eluded physicists for decades.

If you thought regular black holes were about as weird and mysterious as space gets, think again, because for the first time, physicists have successfully simulated what would happen to black holes in a five-dimensional world, and the way they behave could threaten our fundamental understanding of how the Universe works. The simulation has suggested that if our Universe is made up of five or more dimensions - something that scientists have struggled to confirm or disprove - Einstein's general theory of relativity, the foundation of modern physics, would be wrong. In other words, five-dimensional black holes would contain gravity so intense, the laws of physics as we know them would fall apart. There's a lot to wrap your head around here, so let's start with the black holes themselves. In a five-dimensional universe, physicists have hypothesised that black holes are more like very thin rings rather than holes, and as they evolve, they can give rise to a series of 'bulges' that become thinner and thinner over time, and eventually break off to form mini black holes elsewhere. These ring-shaped black holes (or 'black rings') were first proposed in 2002, but until now, no one’s been able to successfully simulate their evolution. This has been made possible thanks to the COSMOS supercomputer at the University of Cambridge in the UK - the largest shared-memory computer in Europe that can perform 38.6 trillion calculations per second.

The problem with five-dimensional black holes is that they’re thought to consist of 'ultragravity rings', where gravity is so intense, it gives rise to a state known as naked singularity. Naked singularity is an event so strange, no one really knows what would occur, except that the laws of general relativity would no longer apply. Einstein’s general theory of relativity is based on how we think gravity governs the behaviour of the Universe. We know that matter in the Universe warps the surrounding fabric of spacetime, and this warping effect is what we refer to as gravity. Since it was first proposed 100 years ago, general relativity has passed every test - everything we observe in the Universe follows its stipulations, but singularity can pose some problems. In a four-dimensional universe (where the fourth dimension is time), singularity is thought to be the point of a black hole where gravity is at its most intense - the centre - and this is surrounded by the event horizon at the black hole's edge. "As long as singularities stay hidden behind an event horizon, they do not cause trouble and general relativity holds - the 'cosmic censorship conjecture' says that this is always the case," says theoretical physicist Markus Kunesch from the University of Cambridge. "As long as the cosmic censorship conjecture is valid, we can safely predict the future outside of black holes." But what if singularity could exist outside a black hole's event horizon? When Physicists have hypothesied that in five or more dimensions, if an object that has collapsed to an infinite density - singularity - is not bound by an event horizon, it becomes naked singularity, and things would get so crazy in and around that object, we'd need to completely rethink our understanding of how physics works. The whole thing just makes me really nervous. "If naked singularities exist, general relativity breaks down," said one of the team, Saran Tunyasuvunakool. "And if general relativity breaks down, it would throw everything upside down, because it would no longer have any predictive power - it could no longer be considered as a standalone theory to explain the Universe." If our Universe only has four dimensions, everything is cool, and ring-shaped black holes and naked singularity are not a thing. But physicists have proposed that our Universe could be made up of as many as 11 dimensions. The problem is that because humans can only perceive three, the only way we can possibly confirm the existence of more dimensions is through high-energy experiments such as the Large Hadron Collider. Kunesch and his team say they've just about hit the limits of what their supercomputer can simulate, but would like to figure out what it is about four-dimensional universes that make naked singularity impossible, and general relativity correct. "If cosmic censorship doesn't hold in higher dimensions, then maybe we need to look at what's so special about a four-dimensional universe that means it does hold," says Tunyasuvunakool.The study has been published in Physical Review Letters,and for more on those 11 dimensions, here's theoretical physicist, Michio Kaku:

Stephen Hawking, in a recent lecture held at the Harvard University, claimed that black holes could be portals to a parallel universe. The celebrated physicist spoke at length about black holes and suggested that they neither store materials absorbed by them nor physical information about the object that created them.

Known as the information paradox, the theory goes against the scientific rule that information on a system belonging to a particular time can be used to understand its state at a different time. Over the years, it has been speculated that black holes do not retain information about the stars from which they are formed, except storing their electrical charge, angular momentum and mass.According to Hawking, as per that theory, it was believed that identical black holes might be formed by an infinite quantity of matter configurations. However, quantum mechanics has signaled the opposite by revealing that black holes could only be formed by particles with explicit wavelengths. If the characteristics of the bodies that create black holes are not deprived, then they include a lot of information that is not revealed to the outside world, according to the physicist."For more than 200 years, we have believed in the science of determinism, that is that the laws of science determine the evolution of the universe" Stephen Hawking said. If information was lost in black holes, we wouldn't be able to predict the future because the black hole could emit any collection of particles."In an earlier talk, Hawking had said things can escape out a black hole, both from the outside and probably through another universe. Currently, Hawking and his colleagues are working on understanding "supertranslations" to offer an explanation for the mechanism via which information is returned from a black hole and encoded on its event horizon.

Today we’re going to have the most surreal conversation. I’m going to struggle to explain it, and you’re going to struggle to understand it. And only Stephen Hawking is going to really, truly, understand what’s actually going on.But that’s fine, I’m sure he appreciates our feeble attempts to wrap our brains around this mind bending concept.All right? Let’s get to it. Black holes again. But this time, we’re going to figure out their temperature.The very idea that a black hole could have a temperature strains the imagination. I mean, how can something that absorbs all the matter and energy that falls into it have a temperature? When you feel the warmth of a toasty fireplace, you’re really feeling the infrared photons radiating from the fire and surrounding metal or stone.And black holes absorb all the energy falling into them. There is absolutely no infrared radiation coming from a black hole. No gamma radiation, no radio waves. Nothing gets out.

Now, supermassive black holes can shine with the energy of billions of stars, when they become quasars. When they’re actively feeding on stars and clouds of gas and dust. This material piles up into an accretion disk around the black hole with such density that it acts like the core of a star, undergoing nuclear fusion.But that’s not the kind of temperature we’re talking about. We’re talking about the temperature of the black hole’s event horizon, when it’s not absorbing any material at all.The temperature of black holes is connected to this whole concept of Hawking Radiation. The idea that over vast periods of time, black holes will generate virtual particles right at the edge of their event horizons. The most common kind of particles are photons, aka light, aka heat.Normally these virtual particles are able to recombine and disappear in a puff of annihilation as quickly as they appear. But when a pair of these virtual particles appear right at the event horizon, one half of the pair drops into the black hole, while the other is free to escape into the Universe.From your perspective as an outside observer, you see these particles escaping from the black hole. You see photons, and therefore, you can measure the temperature of the black hole.

The temperature of the black hole is inversely proportional to the mass of the black hole and the size of the event horizon. Think of it this way. Imagine the curved surface of a black hole’s event horizon. There are many paths that a photon could try to take to get away from the event horizon, and the vast majority of those are paths that take it back down into the black hole’s gravity well.But for a few rare paths, when the photon is traveling perfectly perpendicular to the event horizon, then the photon has a chance to escape. The larger the event horizon, the less paths there are that a photon could take.Since energy is being released into the Universe at the black hole’s event horizon, but energy can neither be created or destroyed, the black hole itself provides the mass that supplies the energy to release these photons.The black hole evaporates.The most massive black holes in the Universe, the supermassive black holes with millions of times the math of the Sun will have a temperature of 1.4 x 10^-14 Kelvin. That’s low. Almost absolute zero, but not quite.

A solar mass black hole might have a temperature of only .0.00000006 Kelvin. We’re getting warmer.Since these temperatures are much lower than the background temperature of the Universe – about 2.7 Kelvin, all the existing black holes will have an overall gain of mass. They’re absorbing energy from the Cosmic Background Radiation faster than they’re evaporating, and will for an incomprehensible amount of time into the future.Until the background temperature of the Universe goes below the temperature of these black holes, they won’t even start evaporating.A black hole with the mass of the Earth is still too cold.Only a black hole with about the mass of the Moon is warm enough to be evaporating faster than it’s absorbing energy from the Universe.As they get less massive, they get even hotter. A black hole with the mass of the asteroid Ceres would be 122 Kelvin. Still freezing, but getting warmer.A black hole with half the mass of Vesta would blaze at more than 1,200 Kelvin. Now we’re cooking!Less massive, higher temperatures.When black holes have lost most of their mass, they release the final material in a tremendous blast of energy, which should be visible to our telescopes.

Some astronomers are actively searching the night sky for blasts from black holes which were formed shortly after the Big Bang, when the Universe was hot and dense enough that black holes could just form.It took them billions of years of evaporation to get to the point that they’re starting to explode now.This is just conjecture, though, no explosions have ever been linked to primordial black holes so far.It’s pretty crazy to think that an object that absorbs all energy that falls into it can also emit energy. Well, that’s the Universe for you. Thanks for helping us figure it out Dr. Hawking.